The invention relates to a level switch employed for detecting the fill level of a medium in a container and for transmitting a switch signal corresponding to the detected level, as well as to a method for detecting the level of a medium in a container and for transmitting a switch signal corresponding to that level.
Level switches of this type have been widely used in practical applications and generally serve as limit detectors for determining whether the medium in the container is above or below a predefined level. These level switches are employed in a wide variety of industrial applications including virtually all aspects of process engineering. While they are frequently used for liquids, they are equally suitable for applications involving pasty and granular materials. Typical liquid applications include spillage and dry-run prevention.
Prior art has described various types of level switches such as vibrating level switches and capacitive level switches. One problem often encountered in practical applications, however, has been that the switch signal, intended to indicate the level of the medium in the container, changes even though the medium has not reached the level at which the switch signal is supposed to change. That problem is often caused by varying extraneous conditions such as temperature fluctuations.